It is important for people to have connectivity to communication services (e.g., telephony, data services, and the like). To facilitate communication between user equipment and various radio access networks (RANs), network entities such as eNodeBs, base stations, and the like typically operate to establish a link between a given wireless-communication device (WCD) (e.g., a handheld mobile radio) and a given network resource, typically using a standard for over-the-air communication, an example of which is 3GPP's Long Term Evolution (LTE), which is one example protocol for a type of wireless communication known as orthogonal frequency division multiplex (OFDM) communication. In addition to mobile radios, some examples of commonly used WCDs include cell phones, smartphones, tablets, notebook computers, laptop computers, and the like. And certainly many other examples of WCDs could be listed as well, as known to those having skill in the art.
One strategy that is often employed in the implementation of wireless networks—to, e.g., achieve improved coverage—involves increasing received signal power through use of redundant, time-synchronized, multiple-site transmissions. In this disclosure, such transmissions are referred to as single-frequency-network-(SFN)-multicast transmissions. One type of SFN-multicast transmissions is known in the art as multicast-broadcast SFN (MBSFN) transmissions, which is a term that is typically associated by those of skill in the art as being a 3GPP term that is particular to the cellular context. The term SFN-multicast transmissions as used in this disclosure applies more generally to transmissions that are broadcast by multiple transmitters (e.g., base stations) in a given wireless network, which could operate according to an OFDM technology. As examples, one or more such wireless networks could operate according to IEEE 802.11, IEEE 802.16, Digital Video Broadcasting (DVB), and/or one or more other wireless-communication technologies deemed suitable by those having skill in the relevant art in a given context or for a given implementation.
It is desirable for people to be able to communicate with one another in as many locations as possible; this is certainly true in the context of public-safety wireless communications for at least the reason that the immediacy and efficacy with which people can communicate with one another are quite often determinative of how positive the ultimate outcome of a given public-safety incident can be. Accordingly, for this reason and others, there is a need for methods and systems for dynamic SFN-multicast symbol synchronization.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.